The present invention relates generally to brominated non-fused aromatic compounds and their use as flame retardants. More particular, the present invention relates to brominated diphenylalkane products that are useful as flame retardants.
Flame retardants are common additives to flammable materials such as polymers. For this reason, it is highly desirable that flame retardants be as white as possible. This enables the production of white polymer formulations. Additionally, even when preparing a colored polymer formulation, polymer formulators often desire that the flame retardant be white. This is so that the desired color can be reproducably obtained from batch to batch, and so that the color imparted to the formulation is due to the pigment selected rather than its combination with the color of the flame retardant.
Brominated diphenylalkanes are known to have flame retardant properties when admixed with flammable macromolecular materials such as polymers. However, to date, prior-reported highly brominated diphenylalkanes prepared using known techniques have not been very white, having Yellowness Indexes (ASTM D 1925-70) well above 10. This compares poorly to the colors of other, commercially available flame retardants, which routinely have Yellowness Indexes less than about 8. As a result, there is a strong need for brominated diphenylalakene products having dramatically improved color characteristics and for processes for their production. The present invention addresses these needs.